/*
 * Copyright (c) 2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { ts, rule } from "qvog-dsl";

const SEVERITY = 2;
const DOC_PATH = 'docs/should-handle-error.md';
const DESCRIPTION = 'Empty catch blocks can hide errors and make debugging difficult. Add proper error handling inside catch clauses.';

export default rule()
  .match(ts.isCatchClause)
  .when(node => {
      // 如果 catch 块是空的，直接报
      if (node.block.statements.length === 0) {
          return true;
      }

      // 如果参数不存在，也不报，说明只是空 catch
      if (!node.variableDeclaration) {
          return false;
      }

      // 检查参数名是否在 catch 块内使用
      const paramName = node.variableDeclaration.name.getText();
      let used = false;

      function checkUsed(n: ts.Node) {
          if (ts.isIdentifier(n) && n.text === paramName) {
              used = true;
          }
          n.forEachChild(checkUsed);
      }

      node.block.forEachChild(checkUsed);
      return !used;
  })
  .report({
      severity: SEVERITY,
      description: DESCRIPTION,
      docPath: DOC_PATH,
  });
